• Wrong Keyword Selection

Most of the websites tend to focus on the keywords after the website has been created rather than researching them at the initial stages. This is one of the most common SEO mistake committed by many which I have come across in my career up till now and you should avoid it totally. If you are a new website search for keywords which are less competitive and can give you high traffic at initial stages.  

• Avoid flash introductions
  

Again this is a very common SEO mistake committed. In the process of making your website attractive to the visitor one tends to forget the search engine and this is where the error is made. Keep in mind that search engine spiders cannot read Javascript and it can really put off the spider therefore try and avoid Flash intros or keep it to a bare minimum. 

• The Title tag
  

It is one of the most important Meta tag from the viewpoint of search engine and visitors. Please don’t leave it empty and also don’t put the keyword ‘home’ on the homepage of your website as this is the biggest blunder which you can commit. Make it informative and user-friendly for both search engine and visitors so that you don’t end up among the losers at the end of the day.  

• Avoid Java Menus
  

I would agree with you that Java can be used for effectively creating interactive menus but alas search engines don’t read them and at the end of the day you cannot ignore search engines after all they are the king but if you are doing Search engine optimization of your website please avoid Java scripting language as much as possible.

• Forgetting SEO is an ongoing process

Some SEO professionals tend to sit idle after gaining top rankings but let me tell you that SEO is an ongoing process as other websites are competing for the top slots too therefore you cannot sleep over your achievements as this can spell doomsday for your website and it will end up reaching the same position from where it started in a very short period of time. So stay careful!!

• Avoid splash or doorway pages

Most of the websites tend to implement splash or doorway pages but I must tell you that it could spell disaster for your website and it will end up in the enemy list of search engines.

• Duplicate Content

Since content creation is a tedious process therefore a number of website owners tend to copy content and end up in the penalty box of search engine or even invite legal action from legitimate content owners so stay away from this practice which could harm the prospects of your website. Avoid such common SEO mistakes and your website would never fall in favor with search engines.